Washing machine and method for controlling the same

ABSTRACT

A washing machine and a method for controlling the same are disclosed. The washing machine includes a rotating washing tub in which laundry is placed and a motor to rotate the washing tub. The method for controlling the same includes performing primary rotation of the motor, detecting a primary laundry amount on the basis of the primary rotation of the motor, supplying, if the detected laundry amount is equal to or greater than a predetermined laundry amount, a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet, performing secondary rotation of the motor, and detecting a secondary laundry amount on the basis of the secondary rotation of the motor. Thus, the washing machine correctly detects the amount of laundry.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application Nos. 10-2010-0065046, filed on Jul. 6, 2010, 10-2010-0065047, filed on Jul. 6, 2010, 10-2010-0074240, filed on Jul. 30, 2010 and 10-2010-0074241, filed on Jul. 30, 2010 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a washing machine and a method for controlling the same, and more particularly to a washing machine for correctly sensing the amount of laundry and a method for controlling the same.

2. Description of the Related Art

Generally, under the condition that a detergent, wash water, and laundry are placed in a drum of a washing machine, the washing machine washes the laundry not only using a washing tub rotated by the driving power of a motor but also using frictional force of the laundry, so that the laundry is hardly damaged and entangled when washed in the drum, resulting in an increased washing effect.

Meanwhile, various methods for effectively sensing the amount of laundry contained in the washing machine have been researched by many developers and companies.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a washing machine and a method for controlling a washing machine and a method for controlling the same, which can correctly detect the amount of laundry.

It is another object of the present invention to provide a washing machine and a method for controlling the same, which can reduce a laundry amount sensing time.

It is another object of the present invention to provide a washing machine that can be operated in response to the detected amount of laundry, and a method for controlling the same.

It is a further object of the present invention to provide a washing machine and a method for controlling the same, which can provide a calibration mode.

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a method for controlling a washing machine which includes a rotating washing tub in which laundry is placed and a motor to rotate the washing tub, the method including performing primary rotation of the motor; detecting a primary laundry amount on the basis of the primary rotation of the motor; supplying, if the detected laundry amount is equal to or greater than a predetermined laundry amount, a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet; performing secondary rotation of the motor; and detecting a secondary laundry amount on the basis of the secondary rotation of the motor.

In accordance with another aspect of the present invention, a method for controlling a washing machine which includes a rotating washing tub in which laundry is placed and a motor to rotate the washing tub includes primarily rotating the motor at a predetermined speed by applying a current to the motor; turning the current flowing in the motor off; detecting a primary laundry amount on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time; supplying, if the detected primary laundry amount is equal to or greater than a predetermined laundry amount, a predetermined amount of water or water corresponding to a predetermined water level to the washing tub; secondarily rotating the motor at a predetermined speed by applying a current to the motor; turning the current flowing in the motor off; and detecting a secondary laundry amount on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time.

In accordance with another aspect of the present invention, a method for controlling a washing machine which includes a rotating washing tub in which laundry is placed and a motor to rotate the washing tub includes rotating the motor; detecting a primary laundry amount or laundry quality on the basis of the rotation of the motor; supplying a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet; after performing the water supply, rotating the motor; detecting a secondary laundry amount or laundry quality on the basis of the rotation of the motor; and displaying a calculated operation time on the detected secondary laundry amount or laundry quality.

In accordance with another aspect of the present invention, a washing machine includes a washing tub in which laundry is placed, configured to be rotated; a motor to rotate the washing tub; and a control unit to perform primary rotation of the motor, to detect a primary laundry amount on the basis of the primary rotation of the motor, to supply, if the detected laundry amount is equal to or greater than a predetermined laundry amount, a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet, to perform secondary rotation of the motor, and to detect a secondary laundry amount on the basis of the secondary rotation of the motor.

In accordance with another aspect of the present invention, a washing machine includes a display; a washing tub in which laundry is placed, configured to be rotated; a motor to rotate the washing tub; and a control unit to perform primary rotation of the motor, to detect a primary laundry amount on the basis of the primary rotation of the motor, to supply a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet, to perform secondary rotation of the motor, to detect a secondary laundry amount on the basis of the secondary rotation of the motor, and to display a calculated operation time on the display on the basis of the detected secondary laundry amount or laundry quality.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows a washing machine according to one embodiment of the present invention;

FIG. 2 is a cross-sectional view illustrating the washing machine shown in FIG. 1;

FIG. 3 is a block diagram illustrating the washing machine shown in FIG. 1;

FIG. 4 is a circuit diagram illustrating a driving unit shown in FIG. 3;

FIG. 5 is a block diagram illustrating an inverter controller shown in FIG. 4;

FIG. 6 is a flowchart illustrating a method for controlling a washing machine according to one embodiment of the present invention;

FIGS. 7 to 9 illustrate more detailed description of the control method shown in FIG. 6;

FIG. 10 is a flowchart illustrating a method for operating the washing machine shown in FIG. 1;

FIG. 11 shows an example of a motor rotation speed in a washing cycle shown in FIG. 1;

FIG. 12 shows an example of a motor rotation speed in a dehydration cycle shown in FIG. 10;

FIG. 13 is a perspective view illustrating a washing machine according to another embodiment of the present invention;

FIG. 14 is a block diagram illustrating the washing machine according to another embodiment of the present invention;

FIG. 15 is a flowchart illustrating a method for controlling the washing machine according to another embodiment of the present invention;

FIGS. 16 to 18 illustrate more detailed description of the control method shown in FIG. 15;

FIG. 19 is a flowchart illustrating a method for controlling the washing machine according to another embodiment of the present invention;

FIG. 20 is a perspective view illustrating a washing machine according to another embodiment of the present invention;

FIG. 21 is a block diagram illustrating the washing machine shown in FIG. 20;

FIG. 22 is a flowchart illustrating a method for controlling the washing machine according to another embodiment of the present invention; and

FIGS. 23 to 25 illustrate mode detailed description of the control method shown in FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below with reference to the attached drawings.

The terms “module” and “unit” used to signify components are used herein to aid in understanding of the components and thus they should not be considered as having specific meanings or roles. Accordingly, the terms “module” and “unit” may be used interchangeably.

FIG. 1 shows a washing machine according to one embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating the washing machine shown in FIG. 1 according to one embodiment of the present invention.

Referring to FIGS. 1 and 2, although the washing machine 100 according to one embodiment of the present invention is designed to perform washing, rinsing, and dehydration cycles of laundry and may conceptually include a drying machine for drying wet laundry, it should be noted that the following description will focus only upon the washing machine for convenience of description and better understanding of the present invention.

The washing machine 100 includes a casing 110 defining the external appearance thereof; a control panel 115 that includes not only a plurality of operation buttons or keys receiving a variety of control commands from a user but also a display for displaying information about an operation state of the washing machine 100, and the like so as to provide a user interface; and a door 113 rotatably coupled to the casing 110 so as to open or close a laundry inlet/outlet hole.

The casing 110 may include a main body 111 forming a space in which a variety of constituent elements of the washing machine 100 are included; and a top cover 112 located above the main body 111 to form a laundry inlet/outlet hole through which laundry can be put into or taken out of an inner tub 122.

Although the casing 110 is designed to include the main body 111 and the top cover 112, the scope or spirit of the casing 110 is not limited thereto and can also be applied to other examples forming the external appearance of the washing machine 100.

In the meantime, although a support rod 135 is exemplarily coupled to the top cover 112 serving as a constituent element of the casing 110, the support rod 135 is not limited thereto and can also be coupled to any fixed part of the casing 110 as necessary.

The control panel 115 includes a plurality of operation keys controlling an operation state of the washing machine 100, and a display 118 arranged at one side of the operation keys 117 to display the operation state of the washing machine 100.

The door 113 may be used to open or close a laundry inlet/outlet hole (not shown) formed in the top cover 112, and may include a transparent member such as tempered glass in such a manner that a user can view the inside part of the main body 111.

The washing machine 100 may include a washing tub 120. The,washing tub 120 may include an outer tub 124 containing wash water, and an inner tub 122 that is rotatably coupled to the outer tub 124 and contains laundry. A balancer 134 for compensating for eccentricity generated in rotation of the washing tub 120 may be located above the washing tub 120.

Meanwhile, the washing machine 100 may include a pulsator rotatably coupled to the bottom of the washing tub 120.

A drive device 138 may provide driving power for rotating the inner tub 122 and/or the pulsator 133. The drive device 138 may include a clutch (not shown) that selectively transmits driving power of the drive device 138 to the inner tub 122 or the pulsator 133 so that only one of the inner tub 122 or the pulsator 133 may be rotated or both may be simultaneously rotated.

Meanwhile, the drive device 138 is operated by the driving unit 220 (i.e., the driving circuit) shown in FIG. 3, and a detailed description thereof will be given below with reference to FIGS. 1 to 3.

On the other hand, a detergent box 114 including a variety of additives (for example, washing detergent, fabric softener, and/or bleach) is coupled to the top cover 112 in a manner that the detergent box 114 can be drawn from the top cover 112, wash water received through a water-supply channel 123 passes through the detergent box 114 and is then provided to the inner tub 122.

Several holes (not shown) are formed in the inner tub 122, so that wash water provided to the inner tub 122 is provided to the outer tub 124 through such holes. The washing machine 100 may include a water supply valve 125 for opening or closing the water-supply channel 123.

Wash water contained in the outer tub 124 may be drained from the outer tub 124 through a drain channel 143. The washing machine may further include a drain valve 145 for opening or closing the drain channel 143 and a drain pump 141 for pumping wash water.

The support rod 135 suspends the outer tub 124 in the casing 110, one end of the support rod 135 is coupled to the casing 110, and the other end is coupled to the outer tub 124 by a suspension 150.

The suspension 150 absorbs or buffers vibration of the outer tub 124 when the washing machine 100 is operated. For example, the outer tub 124 may be vibrated by vibration generated by the rotating inner tub 122. When the inner tub 122 is rotated, the suspension 150 may absorb or buffer vibration caused by eccentricity of laundry contained in the inner tub 122, various factors (e.g., rotation speed or resonance characteristic) of the inner tub 122, and the like.

FIG. 3 is a block diagram illustrating the washing machine shown in FIG. 1.

Referring to FIG. 3, the washing machine 100 controls the driving unit 220 under the control of a control unit 210, and the driving unit 220 may drive a motor 230. Accordingly, the washing machine 100 rotates the washing tub 120 using the motor 230.

The control unit 210 is operated upon receiving an operation signal from any of the operation keys or buttons 1017, so that the washing, rinsing, and dehydration cycles can be performed.

In addition, the control unit 210 may display a washing course, a washing time, a dehydration time, a rinsing time, a current operation state, or the like by controlling the display 118.

The control unit 210 controls the water supply valve 125 to provide the washing tub 120 with water, and controls the drain valve 145 to drain water out of the washing tub 120.

In association with a water supply operation, the washing machine 100 may further include a water-level sensing unit 265 for sensing a water level of the washing tub 120 (e.g., a water level of the outer tub 124). The water-level sensing unit 265 may be implemented as a circuit including resistor and capacitor elements. The lower the water level, the higher the frequency value of the sensed water level. The higher the water level, the lower the frequency value of the sensed water level.

In association with a water supply operation, the washing machine 100 may further include a water amount sensing unit 268 mounted at the water-supply channel 123 may further include a water amount sensing unit 268 for sensing the amount of water supply. Although the water amount sensing unit 268 may be implemented as a floating meter in the embodiment of the present invention, it is not limited thereto and can also be applied to other examples as necessary.

In a subsequent process for sensing the secondary laundry amount, the control unit 210 may adjust the amount of water supplied to the washing machine 120 on the basis of a water-level frequency detected by the water-level sensing unit 265 or the amount of water supply detected by the water amount sensing unit 268.

Preferably, the washing machine may provide the washing tub 120 with water in such a manner that laundry contained in the washing tub 120 is wet. In this case, the amount of water for wetting laundry of the washing tub 120 may be higher than a water level of the empty washing tub and may be lower than the height of laundry contained in the washing tub. That is, the amount of water to be supplied to the washing tub may be an appropriate amount of water capable of partially wetting the laundry.

In this case, the control unit 210 may control the motor 230 in such a manner that laundry contained in the washing tub is well wet with water by forward rotation or reverse rotation of the motor 230 or repeated forward/reverse rotation of the motor 230.

The control unit 210 may operate the motor 230 by controlling the driving unit 220. For example, the control unit 210 may control the driving unit 220 to rotate the motor 230 on the basis of an output current flowing in the motor 230 from a current detection unit 225 and the position signal of the motor 230 from a position sensing unit 220.

Although the detected current signal and the sensed position signal are input to the driving unit 220 in FIG. 3, they are not limited thereto, and may be input to the control unit 210 or may be simultaneously input to all of the control unit 210 and the driving unit 220 as necessary.

The driving unit 220 may be used to drive the motor 230, and may include an inverter (not shown) and an inverter control unit (not shown). In addition, the driving unit 220 may conceptually include a converter capable of providing a DC power to an inverter (not shown).

For example, if an inverter controller (not shown) outputs a PWM switching control signal (See Sic of FIG. 4) to the inverter (not shown), the inverter (not shown) performs a high-speed switching operation so that it can provide AC power having a predetermined frequency to the motor 230.

The driving unit 220 will hereinafter be described with reference to FIG. 4.

Referring to FIG. 4, the control unit 210 may detect the amount of laundry on the basis of a current signal (io) detected by the current detection unit 220 or the position signal (H) detected by the position sensing unit 235. For example, while the washing tub 120 is rotated, the control unit 210 may detect the amount of laundry on the basis of a current value (io) of the motor 230.

The control unit 210 may detect the eccentricity of the washing tub 120, i.e., unbalance (UB) of the washing tub 120. Such eccentricity may be detected on the basis of ripples in the current signal (io) detected by the current detection unit 220 or a rotation speed variation of the washing tub 120.

FIG. 4 is a circuit diagram illustrating the driving unit shown in FIG. 3.

Referring to FIG. 4, the driving unit 220 according to one embodiment of the present invention may include a converter 410, an inverter 420, an inverter controller 430, a DC-terminal voltage detector B, a smoothing capacitor C, and an output current detection unit E. In addition, the driving unit 220 may further include an input current detection unit A, a reactor L, and the like.

The reactor L is arranged between a commercial AC power source (vs) 405 and the converter 410 so that it performs power factor correction or a step-up (or boost) operation. In addition, the reactor L may also limit a harmonic current caused by the high-speed switching of the converter 410.

An input-current detector A may detect an input current (i_(s)) received from the AC power source 405. In order to detect the input current (i_(s)), a current sensor, a current transformer (CT), a shunt resistor, etc. may be used as the input-current detector A. The detected input current (i_(s)) is a pulse-shaped discrete signal, and may be input to the control unit 430.

The converter 410 converts the commercial AC power 405 passing through the reactor L into DC power, and outputs the DC power. Although the commercial AC power 405 of FIG. 4 is shown as single-phase AC power, it should be noted that the commercial AC power 405 may also be three-phase AC power as necessary. The internal structure of the converter 410 may be changed according to types of the commercial AC power 405.

Meanwhile, the converter 410 is comprised of a diode and the like, such that it may also perform a rectifying operation without any additional switching operation.

For example, provided that the commercial AC power 405 is a single-phase AC power, four diodes may be bridged to one another. Provided that the commercial AC power 405 is three-phase AC power, 6 diodes may be bridged to one another.

For example, provided that the commercial AC power 405 is single-phase AC power, a half-bridge converter wherein two switching elements and four diodes are connected to one another may be employed. Provided that the commercial AC power 405 is three-phase AC power, 6 switching elements and 6 diodes may be employed.

The converter 410 may include one or more switching elements, such that it can perform a boosting operation, power factor improvement, and DC-power conversion by the switching operation of the corresponding switching elements.

The smoothing capacitor C is connected to an output terminal of the converter 410. The smoothing capacitor C smooths the converted DC power output from the converter 410, and stores the smoothed DC power. Although the smoothing capacitor C is comprised of only one element in FIG. 5, it may also be comprised of a plurality of elements as necessary to guarantee device stability.

For convenience of description, although the smoothing capacitor C is connected to an output terminal of the converter 410, the scope of the smoothing capacitor C is not limited thereto and DC power may be directly input to the smoothing capacitor C. For example, DC power from a solar battery may be directly input to the smoothing capacitor C, or may be DC/DC converted and input to the smoothing capacitor C. The following description will be focused only upon constituent elements shown in the drawings.

DC power is stored at both ends of the smoothing capacitor C, so that both ends may be referred to as a DC terminal or a DC link terminal.

The DC-terminal voltage detector B may detect a DC-terminal voltage (Vdc) of both ends of the smoothing capacitor C. For this operation, the DC-terminal voltage detector B may include a resistor, an amplifier, and the like. The detected DC-terminal voltage (Vdc) is a pulse-shaped discrete signal, and may be input to the inverter controller 430.

The inverter 420 includes a plurality of inverter switching elements, converts the DC power smoothed by on/off operation of the switching elements into three-phase AC power (va, vb, vc) of a predetermined frequency, and outputs the resultant three-phase AC power (va, vb, vc) to a three-phase motor 230.

The inverter 220 includes upper-arm switching elements (Sa, Sb, Sc) and lower-arm switching elements (S′a, S′b, S′c). In more detail, the inverter 220 includes a total of three pairs (Sa&S′a, Sb&S′b, Sc&S′c) of upper-arm and lower-arm switching elements, wherein the three pairs (Sa&S′a, Sb&S′b, Sc&S′c) are connected to one another in parallel. In addition, one upper-arm switching element (Sa, Sb or Sc) is connected in series to one lower-aim switching element (S′a, S′b or S′c) such that one pair (Sa&S′a, Sb&S′b or Sc&S′c) of upper-aim and lower-arm switching elements is formed. One diode is connected in inverse parallel to one switching element (Sa, S′a, Sb, S′b, Sc or S′c).

The switching elements contained in the inverter 420 receive an inverter switching control signal (Sic) from the inverter controller 430, such that on/off operations of the individual switching elements are performed on the basis of the inverter switching control signal (Sic). As a result, a three-phase AC power having a predetermined frequency is output to the three-phase synchronous motor 230.

The inverter controller 430 may control the switching operation of the inverter 420. For this operation, the inverter controller 430 may receive an output current (io) detected by the output current detection unit E as an input.

The inverter controller 430 may output the inverter switching control signal (Sic) to the inverter 420 so as to control the switching operation of the inverter 420. The inverter switching control signal (Sic) may be a PWM switching control signal, and is generated and output on the basis of the output current value (io) detected by the output current detection unit E. The output of the inverter switching control signal (Sic) will hereinafter be described with reference to FIG. 5.

The output current detection unit (E) detects an output current (i_(o)) flowing between the inverter 420 and the three-phase motor 230. In other words, the output current detection unit (E) may detect current flowing in the motor 230. The output current detection unit E may detect all output currents (i_(a), i_(b), i_(c)) of individual phases, or may also detect a two-phase output current using three-phase equilibrium.

The output current detection unit (E) may be located between the inverter 420 and the motor 230. For current detection, a current transformer (CT), a shunt resistor, or the like may be used as the output current detection unit (E).

When using the shut resistor, three shunt resistors may be located between the inverter 420 and the synchronous motor 230, or may be coupled to one end of each of the three lower-arm switching elements (S′a, S′b, S′c) of the inverter 420. Meanwhile, two shunt resistors may be used using three-phase equilibrium. In contrast, when using only one shunt resistor, a corresponding shunt resistor may be arranged between the above-mentioned capacitor C and the inverter 420.

The detected output current (i_(o)) serving as a pulse-shaped discrete signal may be input to the inverter controller 430, and an inverter switching control signal (Sic) may be generated on the basis of the detected output current (i_(o)). For convenience of description and better understanding of the present invention, it is assumed that the detected output current (i_(o)) is three-phase output currents (ia, ib, ic).

The three-phase motor 230 includes a stator and a rotor. AC power of each phase having a predetermined frequency is applied to a coil of a stator of each phase such that the rotor starts rotating.

Various types of motors 230 may be used, for example, a Surface-Mounted Permanent-Magnet Synchronous Motor (SMPMSM), an Interior Permanent Magnet Synchronous Motor (IPMSM), a Synchronous Reluctance Motor (Synrm), etc. SMPMSM or IPMSM may be a Permanent Magnet Synchronous Motor (PMSM), and Synrm has no permanent magnet.

If the converter 410 includes one or more switching elements, the inverter controller 430 may control the switching operation of the switching element contained in the converter 410. For this operation, the inverter controller 430 may receive the input current (i_(s)) detected by the input current detection unit A. The inverter controller 430 may output a converter switching control signal (Scc) to the converter 410 to control the switching operation of the converter 410. The converter switching control signal (Scc) may be a PWM switching control signal, and may be generated and output on the basis of the input current (is) detected by the input current detection unit A.

The position sensing unit 235 may detect the rotator position of the motor 230. For this operation, the position sensor 235 may include a hall sensor. The sensed rotor position H is input to the inverter controller 430 and is used as a reference for velocity calculation or the like.

FIG. 5 is a block diagram illustrating an inverter controller shown in FIG. 4.

Referring to FIG. 5, the inverter controller 430 includes a first axis transformation unit 510, a velocity calculation unit 520, a current command generator 530, a voltage command generator 540, a second axis transformation unit 550, and a switching control signal output unit 560.

The axis transformation unit 510 receives three-phase output current (ia, ib, ic) detected by the output current detection unit E, and converts the three-phase output current (ia, ib, ic) into two-phase current (iα, iβ) of a stationary reference frame (also called a stationary coordinate system).

The axis transformation unit 510 may convert the two-phase current (iα, iβ) of the stationary reference frame into a two-phase current (id, iq) of a rotation coordinate system.

The velocity calculation unit 520 may calculate speed or velocity ({circumflex over (ω)}_(r)) on the basis of the rotor position signal (H) received from the position sensing unit 235. That is, if the rotor position signal is divided on a time axis, the velocity calculation unit 520 may calculate the speed thereof.

On the other hand, the velocity calculation unit 520 may calculate the calculated position ({circumflex over (θ)}_(r)) and the calculated speed ({circumflex over (ω)}_(r)) on the basis of the rotor position signal (H).

The current command generator 530 generates a current command value (i_(q)*) on the basis of the calculated speed ({circumflex over (ω)}_(r)) and the speed command value (ω_(r)*). For example, the current command generator 530 enables the PI controller 535 to perform Proportional Integral (PI) control on the basis of a difference between the calculated speed ({circumflex over (ω)}_(r)) and the speed command value (ω_(r)*), such that it can generate the current command value (i_(q)*). Although the q-axis current command value (i_(q)*) has been exemplarily used as a current command value in FIG. 5, it should be noted that a d-axis current command value (i_(d)*) may also be generated simultaneously with the q-axis current command value (i_(q)*). In contrast, the d-axis current command value (i_(d)*) may be set to zero (0).

In the meantime, the current command generator 530 may further include a limiter (not shown) preventing a level of each current command value (i_(q)*) from exceeding an allowed range.

The voltage command generator 540 generates d-axis and q-axis voltage command values (ν_(d)* and ν_(q)*) on the basis of not only the d-axis and q-axis currents (i_(d) and i_(q)) axis-transformed to a two-phase rotation coordinate system but also the current command values (i_(d)* and i_(q)*) from the current command generator 530. For example, the voltage command generator 540 enables the PI controller 544 to perform PI control on the basis of a difference between the q-axis current value (i_(q)) and the q-axis current command value (i_(q)*), such that it can generate the q-axis voltage command value (ν_(q)*). In addition, the voltage command generator 540 enables the PI controller 548 to perform PI control on the basis of a difference between the d-axis current value (i_(d)) and the d-axis command value (i_(d)*), such that it can generate the d-axis voltage command value (ν_(d)*). In the meantime, the voltage command generator 540 may further include a limiter (not shown) preventing a level of each voltage command value (ν_(d)* or ν_(q)*) from exceeding an allowed range.

The generated d-axis and q-axis voltage command values (ν_(d)* and ν_(q)*) may be input to the axis transformation unit 550.

The axis transformation unit 550 may receive the position ({circumflex over (θ)}_(r)) calculated by the velocity calculation unit 520 and the d-axis and q-axis voltage command values (ν_(d)* and ν_(q)*), and may then perform axis transformation of the received signals ({circumflex over (θ)}_(r), ν_(d)* and ν_(q)*).

First, the axis transformation unit 550 may convert a two-phase rotation coordinate system into a two-phase stationary coordinate system. In this case, the axis transformation init 550 may use the position signal ({circumflex over (θ)}_(r)) calculated by the velocity calculation unit 520. In addition, the axis transformation unit 550 may convert the two-phase stationary coordinate system into a three-phase stationary coordinate system. By the above-mentioned transformation, the axis transformation unit 550 may output three-phase output voltage command values (ν_(a)*, ν_(b)*, ν_(c)*).

The switching control signal output unit 560 may generate and output a switching control signal (Sic) for a PWM inverter on the basis of the three-phase output voltage command values (ν_(a)*, ν_(b)*, ν_(c)*).

The output inverter switching control signal (Sic) may be converted into a gate drive signal by a gate driver (not shown), so that it may be input to a gate of each switching element contained in the inverter 420. As a result, individual switching elements (Sa, S′a, Sb, S′b, Sc, S′c) contained in the inverter 420 may perform the switching operation.

In accordance with one embodiment of the present invention, the inverter controller 420 may turn the current applied to the motor 230 off when sensing the amount of laundry. That is, all the switching elements (Sa, S′a, Sb, S′b, Sc, S′c) contained in the inverter 420 can be turned off. In addition, during this turn-off period, the inverter controller 430 may correctly detect the amount of laundry on the basis of the position signal (H) detected by the position sensing unit 235 and the calculated deceleration speed or time.

Although the above-mentioned description has exemplarily disclosed that the inverter controller 430 contained in the driving unit 220 is designed to detect the amount of laundry, the scope or spirit of the inverter controller 430 is not limited thereto, the control unit 210 for controlling all operations of the driving unit 220 may also detect the amount of laundry. That is, the position signal (H) detected by the position sensing unit 235 is applied to the control unit 210 through the driving unit 220, so that the control unit 210 may detect the amount of laundry.

Differently from FIGS. 3 and 4, the control unit 210 and the inverter controller 430 may be integrated into one unit as necessary.

FIG. 6 is a flowchart illustrating a method for controlling a washing machine according to one embodiment of the present invention. FIGS. 7 to 9 illustrate more detailed description of the control method shown in FIG. 6;

Referring to FIG. 6, laundry contained in the washing tub is distributed at step S610.

Such laundry distribution may be performed by forward or reverse rotation or repeated forward/reverse rotation at a rotation speed (v0) lower than the first rotation speed (v1) needed for sensing the laundry amount, such that laundry can be distributed into the tub.

In FIG. 7, although the motor is rotated two times at a predetermined rotation speed (v0) during the section (T0), FIG. 7 shows the magnitude of velocity and is irrelevant to directivity. Although the motor is rotated two times at the predetermined rotation speed (v0), it should be noted that the motor may also be rotated only once or more times as necessary.

The control unit 210 or the inverter controller 430 may control the motor 230 to be rotated at the predetermined rotation speed (v0). That is, the corresponding inverter switching control signal (Sic) may be output to the inverter 420.

Meanwhile, the above-mentioned laundry distribution step S610 may be performed optionally as necessary.

The washing machine applies a current to the motor so that the motor is primarily rotated at a predetermined speed at step S615.

The controller 210 or the inverter controller 430 applies AC power to the motor 230 so that the motor 230 can be primarily rotated at a first rotation speed (v1). That is, the corresponding inverter switching control signal (Sic) may be output to the inverter 420. Preferably, the AC power applied to the motor 230 may be represented in a sinusoidal current. As a result, when sensing the amount of laundry, the motor 230 can be correctly driven.

In a first section T1 of FIG. 7, the motor 230 is rotated at a first rotation speed (v1). Preferably, in the first section T1, the motor 230 may be continuously rotated at a predetermined rotation speed during a predetermined time or longer. In addition, such rotation of the motor 230 at a predetermined rotation speed may be maintained during a predetermined time or longer in such a manner that the laundry-amount-sensing time is not excessively prolonged.

Although the number of sections in which the motor is rotated at the first rotation speed is exemplarily set to 1, it is not limited thereto and the number of sections may also be set to 1 or more.

Thereafter, the current applied to the motor is turned off at step S620. The washing machine detects the amount of laundry on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time at step S625.

The control unit 210 or the inverter controller 430 turns the current applied to the motor 230 off. That is, as shown in FIG. 8( a), all three pairs of upper-aim switching elements (Sa, Sb, Sc) and lower-arm switching elements (S′a, S′b, S′c) contained in the inverter 420 are turned off, so that the motor 230 starts decelerating.

In accordance with one embodiment of the present invention, AC power supplied to the motor 230 is turned off so as to detect the amount of laundry, and the amount of laundry is detected using a deceleration speed or time of the motor 230 during at least some parts of the turn-off time.

If the AC power supplied to the motor 230 is turned off, the motor 230 for driving the washing tub 120 including laundry starts decelerating as shown in a second section T2 of FIG. 7. Specifically, the motor 230 is nonlinearly decelerated during a predetermined time starting from the turn-off time, and is linearly decelerated during a predetermined time T3. Then, the laundry contained in the washing tub 120 is untangled, so that the motor 230 is nonlinearly decelerated.

In the embodiment of the present invention, during the linear deceleration time (T3), the washing machine detects the amount of laundry using a deceleration speed or time of the motor 230. As described above, the deceleration speed or time of the motor 230 can be detected in response to the calculated deceleration speed or time of the motor on the basis of the position signal (H) of the position sensing unit 235.

For example, as the deceleration speed or time of the motor is increased or prolonged, this means the presence of a small amount of laundry. As the deceleration speed or time of the motor is reduced or shortened, this means the presence of a large amount of laundry.

For example, if the first rotation speed (v1) of the motor 230 is in the range from 100 rpm to 150 rpm, the motor deceleration speed may be at least some parts of the range from 30 rpm to 90 rpm in the laundry amount sensing section. The deceleration speed section between 30 rpm(vx) and 90 rpm(vy) may correspond to a linear section T3 other than the above-mentioned nonlinear section. As a result, the washing machine can correctly detect the amount of laundry.

On the other hand, in the linear section T3, the washing machine may also detect the amount of laundry not only based on the deceleration speed or time during a few deceleration sections, but also based on the deceleration speed or time during a plurality of deceleration sections. In addition, the washing machine may also calculate the final laundry amount sensing value using an average or weight of several laundry amount sensing values.

On the other hand, such laundry amount sensing process may be performed in the washing process or dehydration process. In accordance with the sensed laundry amount, when detecting the eccentricity sensing process after the laundry amount sensing process, an eccentricity table storing a plurality of allowable values may be changeable. In addition, different eccentricity tables may be used according to the washing cycle or dehydration cycle. Such eccentricity tables may be contained in the controller 210 or the inverter controller 430.

On the other hand, it is determined whether the sensed amount of laundry is equal to or greater than a predetermined amount of laundry at step S630. If the sensed amount of laundry is equal to or greater than the predetermined amount of laundry at step S630, water is supplied to the washing tub at step S635. Then, the washing tub rotates in a forward or reverse direction, or repeatedly rotates in forward/reverse directions at step S640.

The control unit 210 determines whether the sensed amount of laundry is equal to or greater than a predetermined amount of laundry. If the sensed amount of laundry is equal to or greater than the predetermined amount of laundry, the control unit 210 may prepare for sensing a secondary laundry amount. As a result, although wet laundry but not a dry laundry is put into the washing tub 120, the control unit 210 can detect the accurate amount of laundry due to the presence of the secondary laundry amount sensing process.

If the detected laundry amount is equal to or greater than a predetermined amount of laundry, the control unit 210 may adjust the amount of water put into the washing tub 120 on the basis of a water-level frequency detected by the water-level sensing unit 264 or the amount of water supply detected by the water amount sensing unit 268.

The washing machine may provide the washing tub 120 with water in such a manner that laundry contained in the washing tub 120 is wet. In this case, the amount of water for wetting laundry of the washing tub 120 may be higher than a water level of the empty washing tub and may be lower than the height of laundry contained in the washing tub. That is, the amount of water to be supplied to the washing tub 120 may be an appropriate amount of water capable of partially wetting the laundry.

FIG. 9 exemplarily shows that wash water is put into the washing tub 120 to a predetermined water level H2 between the empty water level H0 of the outer tub 124 and a water level H1 including the laundry 810. In FIG. 9, wash water may be put into the washing tub 120 through the water-supply channel 123 under the control of the water-supply valve 125 of the control unit 210.

In this case, the control unit 210 may control the motor 230 in such a manner that laundry contained in the washing tub is well wet with water by forward rotation or reverse rotation of the motor 230 or repeated forward/reverse rotation of the motor 230.

Such laundry wetting may be performed by forward or reverse rotation or repeated forward/reverse rotation at a rotation speed (v0) lower than the first rotation speed (v1).

In FIG. 7, although the motor is rotated two times at a predetermined rotation speed (v0) during a fifth section (T5), FIG. 7 shows the magnitude of velocity but is irrelevant to directivity. Although the motor is rotated two times at the predetermined rotation speed (v0), it should be noted that the motor may also be rotated only once or more times as necessary.

The washing machine applies a current to the motor so that the motor is secondarily rotated at a predetermined speed at step S645.

The controller 210 or the inverter controller 430 applies AC power to the motor 230 so that the motor 230 can be secondarily rotated at a first rotation speed (v1). That is, the corresponding inverter switching control signal (Sic) may be output to the inverter 420. Preferably, the AC power applied to the motor 230 may be represented in a sinusoidal current. As a result, when sensing the amount of laundry, the motor 230 can be correctly driven.

In a sixth section T6 of FIG. 7, the motor 230 is rotated at a first rotation speed (v1). Preferably, in the sixth section T6, the motor 230 may be continuously rotated at a predetermined rotation speed during a predetermined time or longer. In addition, such rotation of the motor 230 at a predetermined rotation speed may be maintained during a predetermined time or longer in such a manner that the laundry-amount-sensing time is not excessively prolonged.

Although the number of sections in which the motor is rotated at the first rotation speed is exemplarily set to 1, it is not limited thereto and the number of sections may also be set to 1 or more.

Thereafter, the current applied to the motor is turned off at step S650. The washing machine detects the amount of laundry on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time at step S655.

The control unit 210 or the inverter controller 430 turns the current applied to the motor 230 off. That is, as shown in FIG. 8( a), all three pairs of upper-arm switching elements (Sa, Sb, Sc) and lower-arm switching elements (S′a, S′b, S′c) contained in the inverter 420 are turned off, so that the motor 230 starts decelerating.

In accordance with one embodiment of the present invention, AC power supplied to the motor 230 is turned off so as to detect the amount of laundry, and the amount of laundry is detected using a deceleration speed or time of the motor 230 during at least some parts of the turn-off time.

If the AC power supplied to the motor 230 is turned off, the motor 230 for driving the washing tub 120 including laundry starts to decelerate as shown in a second section T2 of FIG. 7. Specifically, the motor 230 is nonlinearly decelerated during a predetermined time starting from the turn-off time, and is linearly decelerated during a predetermined time T3. Then, the laundry contained in the washing tub 120 is untangled, so that the motor 230 is nonlinearly decelerated.

In the embodiment of the present invention, during the linear deceleration time (T8), the washing machine detects the amount of laundry using a deceleration speed or time of the motor 230. As described above, the deceleration speed or time of the motor 230 can be detected in response to the calculated deceleration speed or time of the motor on the basis of the position signal (H) of the position sensing unit 235.

For example, as the deceleration speed or time of the motor is increased or prolonged, this means the presence of a small amount of laundry. As the deceleration speed or time of the motor is reduced or shortened, this means a large amount of laundry.

For example, if the first rotation speed (v1) of the motor 230 is in the range from 100 rpm to 150 rpm, the motor deceleration speed may be at least some parts of the range from 30 rpm to 90 rpm in the laundry amount sensing section. The deceleration speed section between 30 rpm(vx) and 90 rpm(vy) may correspond to a linear section T3 other than the above-mentioned nonlinear section. As a result, the washing machine can correctly detect the amount of laundry.

On the other hand, in the linear section T8, the washing machine may also detect the amount of laundry not only based on the deceleration speed or time during a few deceleration sections, but also based on the deceleration speed or time during a plurality of deceleration sections. In addition, the washing machine may also calculate the final laundry amount sensing value using an average or weight of several laundry amount sensing values.

In contrast, considering the amount of supplied water, the control unit 210 may detect the amount of laundry. Subsequently, the control unit 210 may also detect the final amount of laundry using the detected primary laundry amount and the detected secondary laundry amount.

On the other hand, such laundry amount sensing process may be performed in the washing process or dehydration process. In accordance with the sensed laundry amount, when detecting the eccentricity sensing process after the laundry amount sensing process, an eccentricity table storing a plurality of allowable values may be changeable. In addition, different eccentricity tables may be used according to the washing cycle or dehydration cycle. Such eccentricity tables may be contained in the controller 210 or the inverter controller 430.

Although the predetermined rotation speed (v1) of the primary laundry amount sensing process is identical to that of the secondary laundry amount sensing process in the drawings, it is not limited thereto and different rotation speeds may be assigned to the primary and secondary laundry amount sensing processes. In particular, the predetermined rotation speed for the secondary laundry amount sensing process may be higher than that of the primary laundry amount sensing process.

In addition, as can be seen from the drawings, although the primary laundry amount sensing process and the secondary laundry amount sensing process substantially perform the amount of laundry in the same deceleration section from among the turn-OFF time, the amount of laundry may also be detected in different sections as necessary. For example, when sensing the secondary laundry amount after supplying water to the washing tub, the washing machine may detect the amount of laundry in a higher speed section. As a result, the washing machine can correctly detect the amount of laundry.

Thereafter, the washing machine may brake the motor at step S660. The control unit 210 or the inverter controller 430 may brake the motor 230. For example, dynamic braking or plugging braking may be used as such braking method.

For example, in order to perform dynamic braking, as shown in FIG. 8( b), the control unit 210 or the inverter controller 430 may turn upper-arm switching elements (Sa, Sb, Sc) contained in the inverter 420 off and may turn lower-arm switching elements (S′a, S′b, S′c) on. As a result, a closed loop is formed among the motor 230 and lower-arm switching elements (S′a, S′b, S′c), so that the remaining current is consumed and thus the motor 230 stops operation.

In another example, in order to perform dynamic braking, as shown in FIG. 8( b), the control unit 210 or the inverter controller 430 may turn upper-arm switching elements (Sa, Sb, Sc) contained in the inverter 420 off and may turn lower-arm switching elements (S′a, S′b, S′c) on. As a result, a closed loop is formed among the motor 230 and upper-arm switching elements (S′a, S′b, S′c), so that the remaining current is consumed and thus the motor 230 stops operation.

In another example, in order to perform plugging braking, the control unit 210 or the inverter controller 430 may output the switching signal (Sic) to the inverter 420 in an opposite direction to the rotation direction of the motor 230. That is, during the first section T1 or the sixth section T6, it is assumed that phases of AC power applied to three phases of the motor 230 are arranged in the order of a→b→c. In this case, for the plugging braking, phases of AC current applied to three phases of the motor 230 may be rearranged in the order of a→c→b. As a result, the motor 230 may stop operation by an opposite-directional rotation component.

FIG. 7 exemplarily shows the braking section T4 or T9 of the motor 230. As can be seen from FIG. 7, it can be recognized that the motor 230 is braked within a shorter section than natural deceleration. As a result, the laundry amount sensing section can be shortened in time.

FIG. 10 is a flowchart illustrating a method for operating the washing machine shown in FIG. 1.

Referring to FIG. 10, a method of operating the washing machine is largely classified into a washing cycle S910, a rinsing cycle S920, and a dehydration cycle S930.

During the washing cycle S910, a laundry amount sensing section for sensing the amount of laundry contained in the washing tub 120, an eccentricity sensing section for sensing unbalance of the laundry, and a main washing machine section may be implemented, and other examples may also be used as necessary.

During the rinsing cycle S920, a water supply section, a predetermined speed rotation section, a drainage section, and the like may be present, and other examples may also be used as necessary.

During the dehydration cycle S930, a laundry amount sensing section for sensing the amount of laundry contained in the washing tub 120, an eccentricity sensing section for sensing unbalance of the laundry, a preliminary dehydration section, a main dehydration section, and the like may be implemented, and other examples may also be used as necessary.

In accordance with one embodiment of the present invention, in order to detect the amount of laundry in the washing cycle S910 or the dehydration cycle S930, the primary laundry amount is detected on the basis of primary rotation of the motor 230. If the detected laundry amount is equal to or greater than a predetermined laundry amount, wash water is supplied to the washing tub 120 to perform laundry wetting, and the second laundry amount is detected on the basis of secondary rotation of the motor 230. As a result, the washing machine can detect not only the amount of dry laundry but also the amount of wet laundry, and a detailed description thereof will be described later.

FIG. 11 shows an example of a motor rotation speed in the washing cycle shown in FIG. 10.

Referring to FIG. 11, the washing cycle may include a laundry amount sensing section Ta, an eccentricity sensing section Tb, a first washing section Tc and a second washing section Td.

In the laundry amount sensing section Ta, the amount of laundry contained in the washing tub 120 is detected. As shown in FIG. 7, the washing machine detects the primary laundry amount on the basis of primary rotation of the motor 230. If the detected laundry amount is equal to or greater than a predetermined laundry amount, wash water is supplied to the washing tub 120 to perform laundry wetting, and the second laundry amount is detected on the basis of secondary rotation of the motor 230. As a result, the washing machine can detect not only the amount of dry laundry but also the amount of wet laundry.

On the other hand, under the condition that the motor 230 is primarily rotated at a predetermined speed and the flow of current applied to the motor 230 is turned off, the primary laundry amount can be detected. Thereafter, under the condition that the motor 230 is rotated at a predetermined speed and the flow of current applied to the motor 230 is turned off, the secondary laundry amount can be detected. In this way, the amount of laundry can be detected using either deceleration speed of the motor 230 or a deceleration time. Accordingly, the washing machine can correctly detect the amount of laundry, and thus the accurate amount of wash water corresponding to the detected laundry amount can be provided to the washing tub or the level of supplied water can be correctly matched to the detected laundry amount.

After detecting the amount of laundry, motor braking such as dynamic- or plugging-braking is performed so that some parts of the laundry amount sensing section can be shortened in time.

On the other hand, according to the detected laundry amount, the amount of wash water to be supplied to the tub, a water level of wash water, and the like may be determined.

In contrast, as shown in FIG. 7, prior to execution of the laundry amount sensing section Ta, the washing machine may further execute a laundry-distribution section (not shown) in which laundry in the washing tub 120 can be distributed. The laundry-distribution section (not shown) may distribute laundry by forward or reverse rotation or repeated forward/reverse rotation of the washing tub 120 at a speed lower than the first rotation speed (v1).

In the eccentricity sensing section Tb, the eccentricity (UB) of laundry contained in the washing tub 120 is detected. In more detail, the washing tub 120 is rotated at a second rotation speed (v2) so that the eccentricity can be detected. In more detail, the eccentricity can be detected on the basis of the output current (i_(o)) of the motor 230 or ripples in the output current (i_(o)).

In the first washing section Tc or the second washing section Td, if the eccentricity detected in the eccentricity sensing section Tb is equal to or less than a predetermined allowable eccentricity, the washing tub 120 may be rotated at a third rotation speed (v3) or a fourth rotation speed (v4). Under the condition that water supply is completed before the first washing section Tc or the second washing section Td, detergent may be placed in the washing tub 120 so that laundry can be washed. Thereafter, water may be drained out of the washing tub 120.

FIG. 12 shows an example of a motor rotation speed in the dehydration cycle shown in FIG. 10.

Referring to FIG. 12, the dehydration cycle may include a laundry amount sensing section T1, a first eccentricity sensing section Tm, a first dehydration section Tn, a second eccentricity sensing section To, a second dehydration section Tp, a third eccentricity sensing section Tq, and a third dehydration section Tr.

In the laundry amount sensing section Ta, the amount of laundry contained in the washing tub 120 is detected. As shown in FIG. 7, the washing machine detects the primary laundry amount on the basis of primary rotation of the motor 230. If the detected laundry amount is equal to or greater than a predetermined laundry amount, wash water is supplied to the washing tub 120 to perform laundry wetting, and the second laundry amount is detected on the basis of secondary rotation of the motor 230. As a result, the washing machine can detect not only the amount of dry laundry but also the amount of wet laundry.

On the other hand, under the condition that the motor 230 is primarily rotated at a predetermined speed and the flow of current applied to the motor 230 is turned off, the primary laundry amount can be detected. Thereafter, under the condition that the motor 230 is rotated at a predetermined speed and the flow of current applied to the motor 230 is turned off, the secondary laundry amount can be detected. In this way, the amount of laundry can be detected using either deceleration speed of the motor 230 or a deceleration time. Accordingly, the washing machine can correctly detect the amount of laundry, and thus the accurate amount of wash water corresponding to the detected laundry amount can be provided to the washing tub or the level of supplied water can be correctly matched to the detected laundry amount.

After detecting the amount of laundry, motor braking such as dynamic- or plugging-braking is performed so that some parts of the laundry amount sensing section can be shortened in time.

On the other hand, according to the detected laundry amount, the amount of wash water to be supplied to the tub, a water level of wash water, and the like may be determined.

As shown in FIG. 7, prior to execution of the laundry amount sensing section T1, the washing machine according to the present invention may further execute a laundry-distribution section (not shown) in which laundry in the washing tub 120 can be distributed. The laundry-distribution section (not shown) may distribute laundry by forward or reverse rotation or repeated forward/reverse rotation of the washing tub at a speed lower than the first rotation speed (v1).

In the first to third eccentricity sensing sections (Tm, To, Tq), the eccentricity (UB) of laundry contained in the washing tub 120 is detected. In more detail, the washing tub 120 is rotated at a second rotation speed (v2) so that the eccentricity can be detected. In more detail, the eccentricity can be detected on the basis of the output current (i_(o)) of the motor 230 or ripples in the output current (i_(o)).

In the first to third dehydration sections (Tn, Tp, Tr), if the eccentricity detected during the first to third eccentricity sensing sections (Tm, To, Tq) is equal to or less than a predetermined allowable eccentricity, the washing tub 120 can be rotated at third to fifth rotation speeds (v3, v4, v5), respectively. Under the condition that water supply is completed prior to the first dehydration section Tn, the dehydration cycle may be performed. If necessary, water may be drained from the washing tub during the execution of the dehydration process.

Meanwhile, differently from the drawings, not all the first to third eccentricity sensing sections (Tm, To, Tq) are carried out, but only the first eccentricity sensing section Tm may be carried out as necessary.

FIG. 13 shows a washing machine according to another embodiment of the present invention.

The washing machine shown in FIG. 13 is a front-load-type washing machine compared to the top-load-type washing machine of FIG. 1.

The washing machine 1100 includes a cabinet 1110 forming the external appearance of the washing machine 1100; a tub 1120 located in the cabinet 1110 and supported by the cabinet 1110; a drum 1122 located in the tub 1120 so as to wash laundry; a water supply device (not shown) mounted at the outside of a cabinet main frame 1111 so as to provide the cabinet 1110 with wash water; and a drain device (not shown) located under the tub 1120 so as to drain wash water from the tub 1120.

The drum 1122 may include a plurality of through-holes 1122A through which wash water passes. The lifter 1124 enables laundry to move upward to a predetermined height within the drum 1122 in response to rotation of the drum 1122, and enable the laundry located at the predetermined height to move downward in the drum 1122 according to gravity.

The cabinet 1110 may include a cabinet main frame 1111; a cabinet cover 1112 mounted at the front surface of the cabinet main frame 1111 and coupled to the cabinet main frame 1111; a control panel 1115 mounted at an upper part of the cabinet cover 1112 and coupled to the cabinet main frame 1111; and a top plate 1116 mounted at an upper part of the control panel 1115 and coupled to the cabinet main frame 1111.

The cabinet cover 1112 may include a laundry inlet/output hole through laundry can be put into or taken out of the drum 1122, and a door 1113 rotatably coupled to the cabinet cover 1112 in such a manner that the laundry inlet/output hole 1114 can be opened or closed.

The control panel 1115 may include operation keys 1117 for handling an operation state of the washing machine 1110, and a display 1118 mounted at one side of the operation keys to display an operation state of the washing machine 1110.

The operation keys 1117 of the control panel 1115 and the display 1118 may be electrically coupled to the control unit (not shown), and the control unit (not shown), and the control unit (not shown) may control respective constituent elements of the washing machine 1100.

The control panel 1115 may include operation keys 1117 for handling an operation state of the washing machine 1110, and a display 1118 mounted at one side of the operation keys to display an operation state of the washing machine 1110.

The operation keys 1117 of the control panel 1115 and the display 1118 may be electrically coupled to the control unit (not shown), and the control unit (not shown), and the control unit (not shown) may electrically control respective constituent elements of the washing machine 1100.

In the same manner as in the conventional washing machine 100 of FIG. 1, the washing machine 1200 of FIG. 13 may detect the amount of laundry contained in the washing tub 120. In more detail, the washing machine detects the primary laundry amount on the basis of primary rotation of the motor 1130. If the detected laundry amount is equal to or greater than a predetermined laundry amount, wash water is supplied to the washing tub 1120 to perform laundry wetting, and the second laundry amount is detected on the basis of secondary rotation of the motor 1130. As a result, the washing machine can detect not only the amount of dry laundry but also the amount of wet laundry.

On the other hand, under the condition that the motor 1130 is primarily rotated at a predetermined speed and the flow of current applied to the motor 1130 is turned off, the primary laundry amount can be detected. Thereafter, under the condition that the motor 1130 is rotated at a predetermined speed and the flow of current applied to the motor 1130 is turned off, the secondary laundry amount can be detected. In this way, the amount of laundry can be detected using either deceleration speed of the motor 1130 or a deceleration time. Accordingly, the washing machine can correctly detect the amount of laundry, and thus the accurate amount of wash water corresponding to the detected laundry amount can be provided to the washing tub or the level of supplied water can be correctly matched to the detected laundry amount.

After detecting the amount of laundry, motor braking such as dynamic- or plugging-braking is performed so that some parts of the laundry amount sensing section can be shortened in time.

FIG. 14 is a block diagram illustrating the washing machine according to another embodiment of the present invention.

While FIG. 14 is similar to FIG. 3, it should be noted that FIG. 14 further includes an eco key 116 differently from FIG. 3. For convenience of description, the following description will be focused only upon the above-mentioned difference between FIG. 14 and FIG. 3.

The control unit 210 is operated upon receiving an operation signal from the operation keys 117, so that the washing cycle, the rinsing cycle, and the dehydration cycle may be performed.

In addition, the control unit 210 controls the display 118 to display a washing course, an overall operation time, a washing time, a dehydration time, a rinsing time, a current operation state, etc.

On the other hand, the control unit 210 may enter an eco mode upon receiving an operation signal from the eco key 116.

For example, when entering the eco mode, the control unit 210 controls the motor 230 to perform primary rotation. The control unit 210 detects the primary laundry amount on the basis of the primary rotation of the motor 230, and supplies a predetermined amount of water to the washing tub 120 or supplies wash water of a predetermined water level to the washing tub 120 so as to perform laundry wetting. Thereafter, the control unit 210 may detect the secondary laundry amount on the basis of secondary rotation of the motor 230. In conclusion, the washing machine can correctly detect the amount of laundry.

The control unit 210 may display the calculated operation time on the display 118 on the basis of secondarily detected laundry amount or laundry quality. Therefore, a highly-reliable operation time can be provided to the user, and the washing machine can be efficiently operated, resulting in reduction in unnecessary energy consumption.

On the other hand, the control unit 210 may display the calculated operation time on the display 118 on the basis of the primarily detected laundry amount or laundry quality. Preferably, the display 118 may display the calculated operation time in the remaining modes other than the eco mode.

If the washing machine is a top-load-type washing machine shown in FIG. 1, the control unit 210 may supply wash water to the washing tub 120 to a predetermined water level, so that the washing cycle can be performed.

If the washing machine is a front-load-type washing machine shown in FIG. 13, the above-mentioned process for sensing the secondary laundry amount and displaying the operation time in the above-mentioned eco mode may be performed in the washing cycle.

On the other hand, the above-mentioned detecting of the primary and secondary laundry amounts and laundry qualities may be carried out on the basis of current ripples flowing in the motor 230 during the rotation of the motor 230. Alternatively, after a current is input to the motor 230 to rotate the motor 230 and then the flow of current flowing in the motor 230 is severed, the washing machine may also detect the laundry amount or the laundry quality on the basis of deceleration speed or time of the motor 230.

The washing machine shown in FIG. 14 according to another embodiment of the present invention is very similar to that of FIG. 1 or 2. However, differently from FIG. 1 or 2, the control panel 115 of the washing machine shown in FIG. 14 further includes an eco key 116.

That is, the control panel 110 may include an eco key 116 for entering the eco mode, a plurality of operation keys 117 for operating the operation state of the washing machine 100, and a display 118 disposed at one side of the operation keys 117 and displaying an operation state (e.g., an operation time) of the washing machine 100.

Meanwhile, the circuit diagram of the driving unit shown in FIG. 14 may be identical to that of FIG. 4. In addition, the inverter controller of FIG. 5 may be equally applied to the circuit diagram of FIG. 14.

FIG. 15 is a flowchart illustrating a method for controlling the washing machine according to another embodiment of the present invention. FIGS. 16 to 18 illustrate more detailed description of the control method shown in FIG. 15.

As can be seen from FIG. 15, the control method of the washing machine in FIG. 15 is similar to that of FIG. 6.

For example, step S1505 of FIG. 15 may correspond to step S615 of FIG. 6, step S1510 of FIG. 15 may correspond to steps S620 and S625 of FIG. 6, respectively.

In addition, steps S1535, S1540 and S1545 of FIG. 15 may correspond to steps S635, S640, and S645 of FIG. 6, respectively.

Step S1555 of FIG. 15 may correspond to steps S650 and step S655 of FIG. 6.

The following description will be disclosed centering around the above-mentioned differences.

When operating the washing machine, a current is input to the motor so as to detect the laundry amount or the laundry quality, so that the motor is primarily rotated at step S1510. In addition, the washing machine may detect the primary laundry amount or laundry quality on the basis of the motor rotation at step S1515.

FIG. 7 exemplarily shows that the motor 230 is rotated at a first rotation speed (v1) in the first section T1. Although the number of sections in which the motor is rotated at the first rotation speed is exemplarily set to 1 in the drawing, it is not limited thereto and the number of sections may also be set to 1 or more so as to correctly detect the laundry amount or laundry quality.

In order to perform step S1515 for detecting the primary laundry amount or laundry quality, the current applied to the motor may be turned off. The washing machine may detect the amount of laundry on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time. Detailed description of the primary laundry amount sensing process of FIG. 15 will be omitted herein with reference to the primary laundry amount sensing process of FIG. 6.

On the other hand, the primary laundry amount sensing process may also be performed on the basis of either speed ripples generated in constant-speed rotation (e.g., the rotation at speed v1) or ripples in the output current (i_(o)) flowing in the motor.

FIG. 16 exemplarily shows a current ripple component (I_(r)) generated by the movement of laundry contained in the washing tub 120 when a predetermined current (I_(a)) flows in the motor 230 in such a manner that the motor 230 can be continuously rotated at the first rotation speed (v1). The higher the current ripple component (I_(r)), the greater the amount of laundry.

Although not shown in the drawings, the laundry distribution step in the washing tub may also be performed prior to the primary rotation of the motor.

Such laundry distribution may be performed by forward or reverse rotation or repeated forward/reverse rotation at a rotation speed (v0) lower than the first rotation speed (v1) requisite for the laundry amount sensing step.

In FIG. 7, although the motor is rotated two times at a predetermined rotation speed (v0) during a predetermined section (T0), FIG. 7 shows the magnitude of velocity but is irrelevant to directivity. Although the motor is rotated two times at the predetermined rotation speed (v0), it should be noted that the motor may also be rotated only once or more times as necessary.

The control unit 210 or the inverter controller 430 may control the motor 230 to be rotated at a predetermined rotation speed (v0). That is, the corresponding inverter switching control signal (Sic) may be output to the inverter 420.

The control unit 210 determines whether an eco mode is established at step S1520. If the eco mode is established at step S1520, wash water is supplied to the washing tub at step S1535. After that, the washing tub rotates in a forward or reverse direction, or repeatedly rotates in forward/reverse directions at step S1540.

If the eco key 116 shown in FIG. 14 is pressed, the washing machine may enter the eco mode. The control unit 210 may determine whether the eco key 116 is operated or not. If the eco key 116 is operated when the washing machine 100 is operated, the control unit 210 may directly supply water to the washing tub 120 without executing the step S1525. In this case, the washing tub 120 may rotate in a forward or reverse direction, or may repeatedly rotate in forward/reverse directions.

Accordingly, although wet laundry but not dry laundry is put into the washing tub 120, the washing machine can correctly detect the amount of laundry.

In order to detect the secondary laundry amount or laundry quality after supplying wash water to the washing tub, the current is input to the motor so that the motor is secondarily rotated at step S1545. In addition, the washing machine may detect the secondary laundry amount or laundry quality on the basis of the secondary rotation of the motor at step S1555.

The secondary motor rotation and the secondary laundry amount sensing process may be performed in the same manner as in FIG. 6. That is, after the AC power supplied to the motor is turned off, the washing machine may detect the secondary laundry amount. A detailed description thereof will herein be omitted for convenience of description.

On the other hand, the secondary laundry amount sensing process may also be performed on the basis of either speed ripples generated in constant-speed rotation (e.g., the rotation at speed v1) or ripples in the output current (i_(o)) flowing in the motor.

As described above, FIG. 16 exemplarily shows a current ripple component (I_(r)) generated by the movement of laundry contained in the washing tub 120 when a predetermined current (I_(a)) flows in the motor 230 in such a manner that the motor 230 can be continuously rotated at the first rotation speed (v1). The higher the current ripple component (I_(r)), the greater the amount of laundry.

Meanwhile, the control unit 210 may calculate the operation time of the washing machine according to the detected secondary laundry amount or laundry quality at step S1565. For example, if a large amount of laundry is put into the washing tub, the washing time, the rinsing time, and the dehydration time, etc. may be increased. If it is assumed that dry laundry or wet laundry is put into the washing tub, if the dry laundry may have a longer washing time, a longer rinsing time, a rinsing time, etc. than the wet laundry even through the dry laundry has the same amount as the wet dry.

The control unit 210 may establish at least one of an operation course, a speed in eccentricity detection, an acceleration slope in accelerating the motor, a deceleration slope in decelerating the motor, and a maximum rotation speed of the motor.

FIG. 17( b) exemplarily shows the operation time calculated by the secondary laundry amount sensing process. Referring to FIG. 17( b), an object 840 for indicating an eco mode may be displayed on the display 118, and the calculated operation time (0:45), washing time (0:25), rinsing time (0:10), dehydration time (0:10), etc. may also be displayed on the display 118. As a result, a user can recognize the calculated operation time on the basis of the correct laundry amount, resulting in reduction in unnecessary energy consumption.

On the other hand, if it is assumed that the eco mode is not established at step S1520, the washing machine may display the calculated operation time on the display 118 on the basis of the detected primary laundry amount or laundry quality at step S1525. In case of the detected primary laundry amount or laundry quality, if dry laundry is used, the accuracy of the detected laundry amount may be high. However, if some parts of the laundry are wet with water, the accuracy of the detected laundry amount may be deteriorated.

Nevertheless, if the eco mode is not established, the control unit 210 may display the calculated operation time on the display 118 on the basis of the detected primary laundry amount or laundry quality.

FIG. 17( a) exemplarily shows the operation time calculated by the primary laundry amount sensing process. As can be seen from FIG. 17( a), an object 840 for displaying an eco mode is dimly displayed on the display 118, so that a user can recognize that the eco mode was turned off. In addition, the calculated operation time (1:00), washing time (0:30), rinsing time (0:15), dehydration time (0:15), etc. may be displayed on the display 118.

Referring to the result of comparison between FIG. 17( a) and FIG. 17( b), when setting the eco mode, the washing machine correctly detects the amount of laundry after supplying water to the washing tub, so that the overall operation time of the washing machine is reduced as shown in FIG. 17( b). As a result, power consumption can be reduced during the operation of the washing machine.

After performing the laundry amount sensing steps S1510 and S1555, a braking step for stopping the motor may be performed as necessary. For this operation, the control unit 210 or the inverter controller 430 may brake the motor 230. For example, dynamic braking or plugging braking may be used as such braking method.

If the washing machine is a top-load-type washing machine shown in FIG. 1, the control unit 210 may supply wash water to the washing tub 120 to a predetermined water level, so that the washing cycle can be performed.

The washing machine may perform the washing cycle S910, the rinsing cycle S920, and the dehydration cycle S930 shown in FIG. 9 on the basis of the operation time calculated at step S1565 shown in FIG. 15.

The above-mentioned laundry sensing method shown in FIG. 15 may be performed either in the washing cycle of FIG. 11 or in the dehydration cycle shown in FIG. 12.

The above-mentioned method for controlling the washing machine shown in FIG. 15 may also be applied to the front-load-type washing machine shown in FIG. 13.

For this operation, although not shown in FIG. 15, the front-load-type washing machine may further include an eco key (not shown) for entering the eco mode.

Similar to the washing machine 100 shown in FIG. 1, in order to detect the amount of laundry, the primary laundry amount is detected on the basis of primary rotation of the motor 1130. Wash water is supplied to the washing tub 1120 to perform laundry wetting, and the second laundry amount is detected on the basis of secondary rotation of the motor 1130. As a result, the washing machine can detect not only the amount of dry laundry but also the amount of wet laundry.

In the eco mode, the washing machine may display the calculated operation time on the display 1118 on the basis of the detected secondary laundry amount. As a result, the washing machine can recognize the accurate operation time.

As can be seen from FIG. 18, after detecting the primary laundry amount, wash water is supplied to a predetermined water level H3 so as to perform wetting of the laundry 1610. H3 may be identical to a half the height of drum.

On the other hand, if the washing machine is a front-load-type washing machine shown in FIG. 13.

In the above-mentioned eco mode, the process for sensing the secondary laundry amount and displaying the operation time may be performed in the washing cycle.

FIG. 19 is a flowchart illustrating a method for controlling the washing machine according to another embodiment of the present invention. The method for controlling the washing machine of FIG. 19 may be used to detect the amount of laundry, and will hereinafter be described with reference to FIGS. 6 and 19.

First, laundry contained in the washing tub is distributed at step S1910. Step S1910 shown in FIG. 19 may correspond to step S610 shown in FIG. 6.

The washing machine applies a current to the motor so that the motor is rotated at a predetermined speed at step S1920. Step S1920 shown in FIG. 19 may correspond to step S615 shown in FIG. 6.

In a first section T1 of FIG. 7, the motor 230 is rotated at a first rotation speed (v1). Preferably, in the first section T1, the motor 230 may be continuously rotated at a predetermined rotation speed during a predetermined time or longer. In addition, such rotation of the motor 230 at a predetermined rotation speed may be maintained during a predetermined time or longer in such a manner that the laundry-amount-sensing time is not excessively prolonged.

Thereafter, the current applied to the motor is turned off at step S1930. The washing machine detects the amount of laundry on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time at step S1940.

Thereafter, the washing machine may brake the motor at step S1950. The control unit 210 or the inverter controller 430 may brake the motor 230. For example, dynamic braking or plugging braking may be used as such braking method.

In accordance with one embodiment of the present invention, in order to detect the amount of laundry in the washing cycle S910 of FIG. 9, AC power is input to the motor 230 so as to rotate the motor 230 at a predetermined speed (v1), and the flow of current flowing in the motor 230 is then turned off. In more detail, all the switching elements (Sa, S′a, Sb, S′b, Sc, S′c) contained in the inverter 420 are turned off. In as least some sections of the turn-OFF time, the washing machine may correctly detect the amount of laundry using a deceleration speed or time of the motor 230 on the basis of the position signal H detected by the position sensing unit 235. After detecting the amount of laundry, the washing machine may brake the motor so as to reduce some parts of the laundry amount sensing section.

In the laundry amount sensing section Ta, the amount of laundry contained in the washing tub 120 can be detected. As shown in FIG. 7, AC power is input to the motor 230 to rotate the motor 230 at a predetermined speed (v1), and the flow of current flowing in the motor 230 is then turned off. In more detail, all the switching elements (Sa, S′a, Sb, S′b, Sc, S′c) contained in the inverter 420 are turned off. In as least some sections of the turn-OFF time, the washing machine may correctly detect the amount of laundry using a deceleration speed or time of the motor 230 on the basis of the position signal H detected by the position sensing unit 235. After detecting the amount of laundry, the washing machine may brake the motor so as to reduce some parts of the laundry amount sensing section. On the other hand, according to the detected laundry amount, the amount of wash water to be supplied to the tub, a water level of wash water, and the like may be determined.

FIG. 20 is a perspective view illustrating a washing machine according to another embodiment of the present invention.

Although the washing machine of FIG. 20 is very similar to the conventional washing machine of FIG. 1, the control panel of the washing machine of FIG. 20 further includes a calibration key 116 for entering a calibration mode differently from FIG. 1, and as such the same parts will herein be omitted for convenience of description.

FIG. 21 is a block diagram illustrating the washing machine shown in FIG. 20.

The block diagram of FIG. 20 is very similar to that of FIG. 3, and as such only differences between FIG. 20 and FIG. 3 will hereinafter be described for convenience of description and better understanding of the present invention.

On the other hand, the control unit 210 may control the washing machine to enter a calibration mode in various ways. For example, in case of an initial operation of the washing machine, in case of the lapse of a predetermined time after the installation of the washing machine, or upon receiving an operation signal from the calibration key 116, the control unit 210 may control the washing machine to enter a calibration mode.

The calibration mode is used to measure individual reference values required for operating the washing machine, and is used to store the measured values.

For example, the motor 230 rotating the washing tub 120 is rotated under no load state or specific load state, so that the control unit 210 may store, in response to either a current (current value or current ripples) flowing in the motor or a motor speed (speed value or speed ripples), at least one of a reference laundry-amount value, a reference eccentricity value, a reference acceleration slope value, and a reference deceleration slope value in the storage unit 310.

On the other hand, in the calibration mode, not only the above-mentioned reference values but also a reference vibration value of the washing machine may also be stored in the storage unit 310. For these operations, the washing machine may further include a vibration sensing unit 305. The storage unit 310 may store the reference vibration value detected by the vibration sensing unit 305.

The vibration sensing unit 305 may detect vibration of the washing tub 120 in the calibration mode or the operation mode. To accomplish this, the vibration sensing unit 305 may be implemented as a vibration sensor. On the other hand, the vibration sensing unit 305 may be mounted to a specific position at which abnormal vibration of the washing machine 100 can be detected, or may be implemented as an acceleration sensor mounted to a position at which several abnormal vibrations can be simultaneously detected.

The vibration sensing unit 305 may detect vertical vibration generated in response to the bottom surface (or bottom state) on which the washing machine is mounted, or may detect horizontal vibration caused by an out-of-phase or the like. In addition, the vibration sensing unit 305 may simultaneously or optionally detect vibration generated in the washing machine in three-axes directions.

On the other hand, in case of no load state in which no laundry is put into the washing tub 120 or in case of a specific load state in which laundry is put into the washing tub 120, the vibration sensing unit 305 may detect vibration of the washing tub 120.

The storage unit 310 may store a variety of reference values measured in the calibration mode. For example, the storage unit 310 may store, in response to either a current flowing in the motor or a motor speed, at least one of a reference laundry-amount value, a reference eccentricity value, a reference acceleration slope value, and a reference deceleration slope value.

For example, the reference vibration value detected by the vibration sensing unit 305 may be stored in the storage unit. The vibration may be changeable in response to a slope of the bottom at which the washing machine is mounted, a material of the bottom, or the like. For example, as strength of the bottom material is gradually increased and elasticity thereof is gradually lowered, the number of vibrations of the drum may be reduced.

Based on reference values stored in the calibration mode and a current flowing in the rotating motor or a motor speed during the operation mode, the control unit 210 may determine a laundry amount, eccentricity, an acceleration slope, or a deceleration slope. In addition, the control unit 210 may determine the final number of vibrations on the basis of the reference vibration value stored in the calibration mode and the number of vibrations detected in the vibration sensing unit 305.

The control unit 210 may operate the washing machine on the basis of the determined laundry amount, eccentricity, etc. Therefore, the driving efficiency of the washing machine is increased.

On the other hand, if a current mode enters the calibration mode, the control unit 210 may display an object indicating the calibration mode on the display 118. In addition, upon completion of the calibration mode, another object indicating completion of the calibration mode may be displayed on the display 118. As a result, the user can easily recognize a state of the washing machine.

The control unit 210 may detect the state of the washing machine on the basis of the current (i_(o)) detected by the current detection unit 220 or the position signal (H) detected by the position sensing unit 235. For example, during the rotation of the washing tub 120, the control unit 210 may detect the state of the washing machine on the basis of the current value (i_(o)) of the motor 230.

FIG. 22 is a flowchart illustrating a method for controlling the washing machine according to another embodiment of the present invention. FIGS. 23 to 25 illustrate mode detailed description of the control method shown in FIG. 15.

First, in case of an initial operation of the washing machine, or in case of the lapse of a predetermined time after the installation of the washing machine, the control unit 210 may determine the presence or absence of a calibration mode input signal at step S2210. If the presence of the calibration mode input signal is determined at step S2210, the calibration mode is performed. In addition, the calibration mode is displayed on the display at step S2215.

Referring to FIGS. 20 and 21, a calibration key 116 is mounted to the control panel. By the operation of the calibration key, the washing machine may enter the calibration mode.

In the calibration mode, individual reference values used in the washing machine operation may be measured and stored. In the calibration mode, a reference laundry amount value, a reference eccentricity value, a reference acceleration slope value, a reference deceleration slope value, a reference vibration value, or the like may be stored in the storage unit.

In the operation mode of the washing machine after putting laundry into the washing tub, measurement data such as laundry amount or eccentricity may have a considerably large error range. In more detail, the washing machine may be installed under different conditions (e.g., the slope of bottom, the material of the bottom, etc.). In addition, provided that the washing machine is used for a long term after initial installation, the accuracy of measurement data may be deteriorated due to abrasion or separation of inner components of the washing machine, so that the measured laundry amount or eccentricity may have a considerably large error range. In addition, when detecting the laundry amount or eccentricity on the basis of a current flowing in the motor, it may be difficult to correctly measure the amount of laundry and eccentricity due to various factors (e.g., a back electromotive force (Back EMF) component, a noise component of a current, and the like).

In accordance with one embodiment of the present invention, in case of an initial operation of the washing machine or in case of the lapse of a predetermined time after the installation of the washing machine, the washing machine may automatically enter the calibration mode. Alternatively, a calibration mode input signal may also be entered by the user, so that the user enables the washing machine to enter the calibration mode. When the washing machine automatically or manually enters the calibration mode as described above, the motor is rotated under no load state or specific load state, and then calculates the amount of laundry, eccentricity, etc. on the basis of a current flowing in the motor or vibrations of the motor. The calculated laundry amount or eccentricity is set to a reference value or an offset, and then stored in the storage unit 305.

FIG. 24( a) visually shows the calibration mode. An object 820 indicating a calibration mode and a screen image 830 indicating current setting may be displayed on the display 118. As a result, the user can easily recognize that the calibration mode is now progressing.

After that, a current is input to the motor under no load state or specific load state, so that the motor is rotated at step S2220. In addition, the control unit 210 may store a reference laundry amount value or the like on the basis of a current flowing in the motor or the motor speed at step S2225.

In order to measure a reference value in the calibration mode, no load state in which no laundry is put into the washing tub 120 or a specific load state for performing the calibration mode may be provided. Accordingly, the washing machine may measure an accurate reference value.

FIG. 23( a) shows an example of no load state. That is, under the condition that no laundry is put into the washing tub 120 including the inner tub 122 and the outer tub 124, the inner tub 122 rotates by rotation of the motor. On the other hand, differently from FIG. 23( a), the motor may rotate in a reverse direction instead of the forward direction, and may also perform repeated forward/reverse rotation.

A variety of motor rotation patterns may be used in the embodiments of the present invention. For example, a pattern for sensing the amount of laundry or a maximum speed pattern may be used in the embodiments of the present invention.

In the calibration mode, the motor may be rotated according to a washing cycle pattern shown in FIG. 9. In addition, in the calibration mode, the motor may also be rotated according to the dehydration cycle pattern. Accordingly, in the operation mode in which laundry is put into the washing tub so that the washing machine is operated, the accurate laundry amount, the accurate eccentricity, etc. may be determined according to the result of comparison of reference values.

The above-mentioned process for sensing the amount of laundry may be performed on the basis of ripples at a predetermined speed (v1). FIG. 11 exemplarily shows a current ripple component (I_(r)) generated by the movement of laundry contained in the washing tub 120 when a predetermined current (I_(a)) flows in the motor 230 in such a manner that the motor 230 can be continuously rotated at the first rotation speed (v1). The higher the current ripple component (I_(r)), the greater the amount of laundry.

On the other hand, after the lapse of the predetermined speed (v1), the laundry amount sensing process may also be preformed using deceleration speed or time of the motor 230 in a deceleration section. The deceleration speed or time of the motor 230 may be detected according to the deceleration speed or time calculated on the basis of the position signal (H) of the position sensing unit 235. For example, as the deceleration speed or time of the motor is increased or prolonged, this means the presence of a small amount of laundry. As the deceleration speed or time of the motor is reduced or shortened, this means the presence of a large amount of laundry.

In the calibration mode, no laundry is contained in the washing tub so that a reference laundry amount value may be determined using ripple components or the deceleration speed or time in the deceleration section. In addition, the determined reference laundry amount value may be stored in the storage unit 305.

In the eccentricity sensing section Tb shown in FIG. 11, the eccentricity (UB) of laundry contained in the washing tub 120 can be detected. In more detail, the washing tub 120 is rotated at a second rotation speed (v2) so that the eccentricity can be detected. In more detail, the eccentricity can be detected on the basis of the output current (i_(o)) of the motor 230 or ripples of the output current (i_(o)).

In the calibration mode, no laundry is contained in the washing tub so that a reference eccentricity value may be determined using the output current (i_(o)) of the motor 230, ripples in the output current (i_(o)), or speed ripple components of the motor 230. The determined reference eccentricity value may be stored in the storage unit 305.

In the first washing section Tc or the second washing section Td of FIG. 11, the washing tub 120 may be rotated at a third rotation speed (v3) or a fourth rotation speed (v4). In this case, the rising or falling time of the third rotation speed (v3) or the fourth rotation speed (v4) may be measured, and a reference acceleration speed value or a reference deceleration speed value may be stored in the storage unit.

The dehydration cycle of FIG. 10 may include a laundry amount sensing section T1, a first eccentricity sensing section Tm, a first dehydration section Tn, a second laundry amount sensing section To, a second dehydration section Tp, a third eccentricity sensing section Tq, and a third dehydration section Tr.

The laundry amount sensing section T1 in the calibration mode may determine a reference laundry amount value in the same manner as in laundry amount sensing section Ta of FIG. 11.

In the calibration mode, the eccentricity sensing section (Tm, To or Tq) may also determine a reference eccentricity value in the same manner as in the eccentricity sensing section Tb of FIG. 11.

In the dehydration section (Tn, To or Tr), the washing tub 120 may be rotated at a third rotation speed (v3), a fourth rotation speed (v4), or a fifth rotation speed (v5). In this case, the rising or falling time of the third rotation speed (v3), the fourth rotation speed (v4) or the fifth rotation speed (v5) may be measured, and a reference acceleration speed value or a reference deceleration speed value may be stored in the storage unit.

Upon completion of the calibration mode, the washing machine may display information regarding the calibration mode completion on the display at step S2230.

After measurement completion of all the above-mentioned reference values, if the calibration mode is ended, the control unit 210 may display information regarding the calibration mode completion on the display 118.

FIG. 24( b) exemplarily shows the completion of calibration mode. As can be seen from FIG. 24( a), an object 820 indicating the calibration mode is dimly displayed on the display 118, or a screen image 835 indicating setting completion may be displayed on the display 118. As a result, the user can easily recognize completion of the calibration mode.

After that, the control unit 210 may determine whether a current mode is an operation mode at step S2235. If the operation mode is determined, the motor is rotated at step S2240. In addition, the control unit 210 may determine the amount of laundry or the like on the basis of the stored reference value, and a current flowing in the motor or a motor speed at step S2245.

By the operation key 117, the operation mode performed. At this time, the operation mode may be classified into the washing cycle, the rinsing cycle, and the dehydration cycle after the laundry is put into the washing tub 120.

FIG. 23( b) exemplarily shows the rotation of the washing tub after putting laundry into the washing tub. That is, under the condition that laundry 810 is put into the washing tub 120 including the inner tub 122 and the outer tub 124, the inner tub 122 rotates by rotation of the motor. On the other hand, differently from FIG. 23( b), the motor may rotate in a reverse direction but not the forward direction according to the operation mode categories, and may also perform repeated forward/reverse rotation. In the operation mode, the washing cycle may be exemplarily shown in FIG. 11, and the dehydration cycle may be exemplarily shown in FIG. 10.

On the other hand, the rinsing cycle may be classified into a water-supply section, a constant-speed rotation section, a drain section, and the like, and it is not limited thereto and can also be applied to other examples.

In the laundry amount sensing section Ta of the washing cycle or the laundry amount sensing section T1 of the dehydration cycle, the control unit 210 may determine the final laundry amount using the reference laundry amount value stored in the calibration mode and the laundry amount measured in the operation mode. For example, the reference laundry amount value serving as an offset component may be subtracted from the measured laundry amount value during the operation mode, so that the final laundry amount can be correctly determined. As a result, the washing machine can be efficiently driven and operated according to the determined laundry amount.

In the eccentricity sensing section Tb of the washing cycle or the laundry amount sensing section Tm of the dehydration cycle, the control unit 210 may determine the final laundry amount using the reference eccentricity value stored in the calibration mode and the eccentricity value measured in the operation mode. For example, the reference eccentricity value serving as an offset component may be subtracted from the measured eccentricity value during the operation mode, so that the final eccentricity value can be correctly determined. As a result, the washing machine can be efficiently driven and operated according to the determined eccentricity.

In the third speed section v3, the fourth speed section v4, and the fifth speed section v5 in the washing cycle or dehydration cycle, the control unit may determine the final acceleration speed value or the final deceleration speed value not only using the reference acceleration speed value or reference deceleration speed value stored in the calibration mode, but also using the acceleration or deceleration speed value measured in the operation mode. As a result, the washing machine can be efficiently driven.

On the other hand, the calibration mode shown in FIG. 22 may be performed together with the control method of FIG. 6, the control method of FIG. 15, or the control method of FIG. 19. That is, in case of an initial operation of the washing machine, in case of the lapse of a predetermined time after the installation of the washing machine, or upon receiving a calibration mode input signal, the control method of FIG. 6, 16 or 18 may be performed after completion of the calibration mode.

On the other hand, the control method shown in FIG. 22 may also be applied to the front-load-type washing machine shown in FIG. 13.

For the above-mentioned operation, although not shown in FIG. 13, the front-load-type washing machine may further include a calibration key (not shown) for enabling the washing machine to enter the calibration mode.

Similar to the washing machine 100 of FIG. 1, the washing machine 1100 of FIG. 13 may rotate the motor under no load state or specific load state in the calibration mode, so that various reference values such as reference laundry and eccentricity amount values may be measured and stored.

In the operation mode, the final laundry amount value or the final eccentricity value may be determined using the measured laundry amount and eccentricity values, prestored reference values, and the like. As a result, the washing machine can be efficiently driven and operated.

FIG. 25( a) shows an example of no load state. That is, under the condition that no laundry is put into the drum 1122, the drum 1122 rotates by rotation of the motor. On the other hand, differently from FIG. 25( a), the drum 1122 may rotate in a reverse direction instead of the forward direction, and may perform repeated forward/reverse rotation.

FIG. 25( b) exemplarily shows that laundry is put into a washing tub and the washing tub starts to rotate during the operation mode. That is, under the condition that the laundry 1310 is put into the drum 1122, the drum 1122 may rotate by rotation of the motor. On the other hand, differently from FIG. 25( ba), the drum 1122 may rotate in a reverse direction instead of the forward direction, and may perform repeated forward/reverse rotation.

The washing machine according to the foregoing exemplary embodiments is not restricted to the exemplary embodiments set forth herein. Therefore, variations and combinations of the exemplary embodiments set forth herein may fall within the scope of the present invention.

The washing machine according to the foregoing exemplary embodiments may be implemented as code that can be written on a computer-readable recording medium and thus read by a processor. The computer-readable recording medium may be any type of recording device in which data is stored in a computer-readable manner.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made without departing from the spirit and scope of the present invention as defined by the following claims.

As is apparent from the above description of embodiments of the present invention, the washing machine according to the embodiments of the present invention detects a primary amount of laundry on the basis of primary rotation of the motor. If the detected laundry amount is equal to or greater than a predetermined laundry amount, water is supplied to the washing tub, and then a secondary amount of wet laundry is detected on the basis of secondary rotation of the motor, such that the amount of laundry can be detected in the washing machine. As a result, not only the amount of dry laundry but also the amount of wet laundry can be correctly detected.

On the other hand, under the condition that the motor is primarily rotated at a predetermined speed and the flow of current applied to the motor is turned off, the primary laundry amount can be detected. Thereafter, under the condition that the motor is rotated at a predetermined speed and the flow of current applied to the motor is turned off, the secondary laundry amount can be detected. In this way, the amount of laundry can be detected using either deceleration speed of the motor or a deceleration time. Accordingly, the washing machine according to the present invention can correctly detect the amount of laundry, and thus the accurate amount of wash water corresponding to the detected laundry amount can be provided to the washing tub or the level of supplied water can be correctly matched to the detected laundry amount.

After detecting the amount of laundry, motor braking such as dynamic- or plugging- braking is performed so that some parts of the laundry amount sensing section can be shortened in time.

In accordance with another embodiment of the present invention, the washing machine detects a primary amount of laundry on the basis of the motor rotation. In order to make wet laundry, water is supplied to the washing tub, and then a secondary amount of wet laundry is detected on the basis of the motor rotation, such that the amount of laundry can be detected in the washing machine. As a result, the amount of laundry can be correctly detected.

In addition, the washing machine according to the embodiments of the present invention can display the calculated operation time on the basis of the detected secondary laundry amount, such that a highly reliable result can be provided to a user.

Therefore, the washing machine can be driven and operated in response to the above-mentioned result, so that an eco mode such as energy saving can be efficiently carried out.

The washing machine may include a separate eco key or button, so that it can easily enter the eco mode.

In accordance with another embodiment of the present invention, in order to detect the amount of laundry, the washing machine applies AC power to the motor so as to allow the motor to rotate at a predetermined speed, and then turns the current applied to the motor off. Specifically, in at least some sections of the turn-off period of the current, the washing machine may use a deceleration speed or time of the motor. As a result, the washing machine can correctly detect the amount of laundry, and thus the accurate amount of wash water corresponding to the detected laundry amount can be provided to the washing tub or the level of supplied water can be correctly matched to the detected laundry amount.

After detecting the amount of laundry, motor braking such as dynamic- or plugging-braking is performed so that some parts of the laundry amount sensing section can be shortened in time.

In accordance with another embodiment of the present invention, the washing machine rotates the motor under no load state during a calibration mode, so that it can predetermine a variety of reference values to be used when operating. In a subsequent operation mode, the amount of laundry, the eccentricity, and the like may be correctly determined using the above-mentioned reference values. Therefore, the operation efficiency of the washing machine can be improved.

In addition, a separate calibration key is provided to the washing machine, so that the user may control the washing machine to easily enter a calibration mode.

In addition, a state of the calibration mode or the completion of the calibration mode is displayed on the display of the washing machine, so that a user can easily recognize whether the calibration mode is ended or not.

In conclusion, the washing machine can be efficiently driven and operated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. A method for controlling a washing machine which includes a rotating washing tub in which laundry is placed and a motor to rotate the washing tub, the method comprising: performing primary rotation of the motor; detecting a primary laundry amount on the basis of the primary rotation of the motor; supplying, if the detected laundry amount is equal to or greater than a predetermined laundry amount, a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet; performing secondary rotation of the motor; and detecting a secondary laundry amount on the basis of the secondary rotation of the motor.
 2. The method according to claim 1, further comprising: after performing the primary rotation of the motor, turning a current flowing in the motor off; and after performing the secondary rotation of the motor, turning a current flowing in the motor off.
 3. The method according to claim 1, wherein the amount of water supplied to the washing tub is higher than a water level of an empty washing tub and is lower than a height of the laundry contained in the washing tub.
 4. The method according to claim 1, further comprising: after supplying water to the washing tub, performing forward or reverse rotation of the washing tub, or performing repeated forward/reverse rotation
 5. The method according to claim 2, wherein the laundry amount detecting operation is performed in a specific section in which rotation speed of the motor is linearly reduced from among the current-OFF time.
 6. The method according to claim 1, further comprising: after detecting the laundry amount, braking the motor.
 7. The method according to claim 2, wherein the primary and secondary laundry amount detection includes: detecting the laundry amount on the basis of acceleration speed or time of the motor in a plurality of sections from among the current-OFF time.
 8. The method according to claim 1, wherein the primary laundry amount detection and the secondary laundry amount detection are performed in different deceleration speed sections of the motor.
 9. A method for controlling a washing machine which includes a rotating washing tub in which laundry is placed and a motor to rotate the washing tub, the method comprising: primarily rotating the motor at a predetermined speed by applying a current to the motor; turning the current flowing in the motor off; detecting a primary laundry amount on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time; supplying, if the detected primary laundry amount is equal to or greater than a predetermined laundry amount, a predetermined amount of water or water corresponding to a predetermined water level to the washing tub; secondarily rotating the motor at a predetermined speed by applying a current to the motor; turning the current flowing in the motor off; and detecting a secondary laundry amount on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time.
 10. A method for controlling a washing machine which includes a rotating washing tub in which laundry is placed and a motor to rotate the washing tub, the method comprising: rotating the motor; detecting a primary laundry amount or laundry quality on the basis of the rotation of the motor; supplying a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet; after performing the water supply, rotating the motor; detecting a secondary laundry amount or laundry quality on the basis of the rotation of the motor; and displaying a calculated operation time on the basis of the detected secondary laundry amount or laundry quality.
 11. The method according to claim 10, wherein the displaying of the calculated operation time is performed when an eco mode is selected.
 12. The method according to claim 10, further comprising: before supplying water to the washing tub, displaying a calculated operation time on the basis of the detected primary laundry amount or laundry quality.
 13. The method according to claim 10, wherein the secondary laundry amount detection and the operation time displaying are performed in a washing cycle.
 14. The method according to claim 10, wherein the primary and secondary laundry amount or laundry quality detection detects the laundry amount or laundry quality on the basis of current ripples flowing in the motor during the motor rotation.
 15. The method according to claim 10, further comprising: turning the current flowing in the rotating motor off, and wherein the primary and secondary laundry amount or laundry quality detection detects the laundry amount or laundry quality on the basis of a deceleration speed or time of the motor in at least some sections of the current-OFF time.
 16. The method according to claim 10, further comprising: rotating the motor under a no load state or specific load state in a calibration mode; storing at least one of a reference laundry-amount value, a reference eccentricity value, a reference acceleration slope value, and a reference deceleration slope value on the basis of a current flowing in the motor and a motor speed; rotating the motor in an operation mode; and determining at least one of a laundry amount, eccentricity, acceleration slope, and deceleration slope on the basis of the stored reference values and a current flowing in the motor and a motor speed.
 17. A washing machine comprising: a washing tub in which laundry is placed, configured to be rotated; a motor to rotate the washing tub; and a control unit to perform primary rotation of the motor, to detect a primary laundry amount on the basis of the primary rotation of the motor, to supply, if the detected laundry amount is equal to or greater than a predetermined laundry amount, a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet, to perform secondary rotation of the motor, and to detect a secondary laundry amount on the basis of the secondary rotation of the motor.
 18. The washing machine according to claim 17, further comprising: a water-level sensing unit to detect a water level of the washing tub.
 19. The washing machine according to claim 17, further comprising: a water amount sensing unit to detect an amount of water supplied to the washing tub.
 20. The washing machine according to claim 17, further comprising.: an inverter to convert predetermined DC power into AC power having a predetermined frequency, and to output the AC power to the motor; an output current detection unit to detect an output current flowing in the motor; and a position sensing unit to detect a rotor position of the motor, wherein the inverter includes three pairs of switching elements, each pair including an upper-arm switching element and a lower-arm switching element, and the control unit, after the primary or secondary rotation of the motor, turns the three pairs of switching elements contained in the inverter off in such a manner that a current flowing in the motor is turned off.
 21. The washing machine according to claim 17, further comprising: an inverter to convert predetermined DC power to AC power having a predetermined frequency, and to output the AC power to the motor; an output current detection unit to detect an output current flowing in the motor; and a position sensing unit to detect a rotor position of the motor, wherein the inverter includes three pairs of switching elements, each pair including an upper-arm switching element and a lower-arm switching element, and the control unit, after detecting the laundry amount, turns only lower-arm or upper-arm switching elements contained in the inverter on.
 22. A washing machine comprising: a display; a washing tub in which laundry is placed, configured to be rotated; a motor to rotate the washing tub; and a control unit to perform primary rotation of the motor, to detect a primary laundry amount on the basis of the primary rotation of the motor, to supply a predetermined amount of water or water corresponding to a predetermined water level to the washing tub in such a manner that the laundry becomes wet, to perform secondary rotation of the motor, to detect a secondary laundry amount on the basis of the secondary rotation of the motor, and to display a calculated operation time on the display on the basis of the detected secondary laundry amount or laundry quality.
 23. The washing machine according to claim 22, further comprising: an eco key to establish and entering an eco mode, wherein the control unit controls the display to display the calculated operation time on the display according to the established eco mode.
 24. The washing machine according to claim 22, further comprising: a storage unit, in a calibration mode, to store at least one of a reference laundry-amount value, a reference eccentricity value, a reference acceleration slope value, and a reference deceleration slope value on the basis of a current flowing in the motor and a motor speed, wherein the control unit rotates the motor under a no load state or specific load state in a calibration mode, rotates the motor in an operation mode, and determines at least one of a laundry amount, eccentricity, acceleration slope, and deceleration slope on the basis of the stored reference values and a current flowing in the motor and a motor speed.
 25. The washing machine according to claim 24, further comprising: a calibration key to enter the calibration mode, wherein the control unit performs the calibration mode in case of an initial operation, in case of a lapse of a predetermined time after installation of the washing machine, or in case of execution of the calibration key. 